本试验旨在探讨油酸对奶牛乳腺上皮细胞内甘油三酯含量和乳脂肪合成相关基因表达的影响.选取中国荷斯坦奶牛乳腺上皮细胞(BMECs)为试验材料,经纯化培养后,培养基中添加0(对照)、50、100、200、400μmol/L油酸,继续培养24 h.通过四甲基偶氮唑盐(MTT)比色法检测细胞活力;利用试剂盒检测胞内甘油三酯的含量;采用实时定量PCR法检测乳脂肪合成相关基因的表达.结果表明:油酸浓度为200、400μmol/L时,BMECs相对增殖率显著低于对照组与其他试验组(P＜0.05);添加100、200μmol/L的油酸促进了胞内甘油三酯的合成(P＜0.05);添加油酸上调了二酰甘油酰基转移酶(DGAT)基因表达量,50μmol/L的油酸显著上调了乙酰辅酶A羧化酶(ACG)和过氧化物酶体增殖物激活受体γ(PPARGγ)基因表达量(P＜0.05),100～400μmol/L的油酸显著抑制了硬脂酰辅酶A去饱和酶(SCD)、脂肪酸结合蛋白3(FABP3)、固醇调节原件结合蛋白1(SREBP-1)基因表达量.综上所述,50～100 μ mol/L的油酸对BMECs乳脂肪合成具有较好的促进效果.%The aim of this study was to determine the effects of oleic acid on triglyceride content and gene expressions involved in milk fat synthesis in bovine mammary epithelial cells (BMECs).Mammary epithelial cells from Chinese Holstein cows were culture and purification.Different concentrations [0(control),50,100,200,400 μtmol/L] of oleic acid were added in culture medium for a 24 h cultivation.Cell viability was detected by thiazoly blue tetrazolium bramide (MTT);triglyceride (TAG) content was measured by using TAG determination kit;gene expressions involved in milk fat synthesis were measured by real-time quantitative (RT-qPCR).The results showed that 200 μmol/L and 400 μmol/L oleic acid significantly inhibited the proliferation of BMECs compared with control and other experimental groups (P＜0.05);100 μmol/L and 200 μmol/L oleic acid significantly promoted TAG synthesis in BMECs (P＜0.05).SCD,FABP3 and SREBF1 gene expression were significantly suppressed by addition of oleic acid (P＜0.05),however,DGAT2 gene expression was increased.50 μ mol/L oleic acid significantly increased ACC and PPARGγ gene expression(P＜0.05).In conclusion,50 to 100 μmol/L oleic acid is an optimal level considering its improvement effects on milk fat synthesis.
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